In a ruling this week, Judge William Alsup said that plaintiffs can sue greenhouse-gas emitters in federal court. That’s a big reversal. So far, the courts have held that it’s up to the EPA and lawmakers — not judges — to bring polluters into line.

In this case, the cities of Oakland and San Francisco sued a bunch of oil companies for contributing to climate change, raising sea levels and damaging their waterfronts. Because federal courts had previously said they wouldn’t regulate polluters, the cities were trying to move their lawsuit into the California court. If federal court wouldn’t punish polluters, the lawyers figured, maybe state court would.

Alsup denied the cities’ motion to move to state court. But instead of bowing to precedent and punting responsibility over to the EPA, he’s letting the lawsuit go to trial — in federal court.

“[The oil companies] got what they wanted; but they may be sorry they did,” said Ken Adams, lawyer for the Center for Climate Integrity, in a statement.

Of course, after opening this door, the courts could very well slam it shut again. The Supreme Court unanimously ruled in 2011 that it’s the job of Congress and regulators, not the court, to police emissions. But that decision concerned an American electric utility. Alsup said this case was different because the cities are suing international corporations.

This story was originally published by Grist with the headline A federal judge just opened the door to more climate lawsuits. on Mar 2, 2018.